With the technology developing, the image quality of LCD (Liquid Crystal Display) has been improved greatly to open up new fields such as personal electronic products in which traditional CRT display (Cathode Ray Tube display) cannot substitute for LCD. To meet the demand of portability by many products in the related fields, however, many properties, such as weight, thickness, size and low power consumption, of LCD, need to be improved.
FIG. 1 is a top view showing a conventional design for a packaged integrated circuit (IC) device 13 connecting to a PCB (printed circuit board) 11. FIG. 2 is a sectional view showing the structure along the line I-I′ of FIG. 1. As shown in FIGS. 1 and 2, packaged IC device 13 has a plurality of leads 15. The designed circuit (not shown) is formed on PCB 11 with a plurality of connections 17, wherein the connectors 17 are made of exposed conductive material. The leads 15 of packaged IC device 13 are electrically connected with the connectors 17 of PCB 11 to transfer signal. However, large contact area as shown in FIG. 1 is needed to accomplish the connection between the packaged IC device 13 and PCB 11. Therefore, a conventional design for connection cannot meet the recent demand of LCD portability.
To overcome the drawbacks of conventional connection occupied large area, developing new connective technology between the flip chip and the substrate, such as the electrical connection surface of integrated circuit device is connected directly to the substrate to form an electrical channel, is developed. FIG. 3 is a top view showing a new design for flip chip connecting to glass substrate. FIG. 4 is a sectional view showing the structure along the line II-II′ of FIG. 3. The designed circuit (not shown) is formed on glass substrate 21 in FIG. 4, wherein the connectors 27 are made of exposed conductive material. IC 23 has a plurality of bumps 25. Bumps 25 are electrically connected with the connectors 27 to transfer signal. As shown in FIG. 3, connection between IC 23 and glass substrate 21 only occupies the area of the size of IC 23.
After connection between IC and glass substrate, display panel can show the information depending on the signal transferred from IC. Therefore, proper alignment of the connection will improve the display quality. Thus, it is important to have proper alignment for the connection between IC and glass substrate.
However, such new connective technology between flip chip and substrate has a difficulty in process. Because one characteristic of flip chip technology is that the IC electrical bumps are connected directly down to the connections of the substrate, human eyes may not be able to assist in checking the alignment during connecting process.
FIG. 5 is a sectional view showing the structure and method of conventional testing design for flip chip connection process. The glass substrate 51 has a plurality of connectors 57, and testing IC 53 has a plurality of conductive bumps 55 and conductive lines 59 connected each of conductive bumps 55. Each of conductive bumps 55 is electrically connected with each of the connections 57 to form an electrical channel, as arrow 56 shown. However, the structure and method of conventional testing design need extra testing IC to evaluate ability of equipment and process, and the testing IC cannot be applied in liquid crystal display (TFT-LCD) product so that it will increase the cost and waste time.
Therefore, there is a need to design a structure and related methods to check alignment and resistance of each connecting point whether it meets the product specification requirement.